An East Bay man was pretty happy when PG&E told him that he had been paying too much for his electricity and was getting money back, but when he didn't get back all he thought he was owed, he decided to call 7 On Your Side.

David Nelson's Oakland condo has all-electric appliances -- the stove, oven, even the heaters. So he expected a sizable electric bill, but nothing as high as what he received.

"We just assumed something was wrong but they could never tell us what it was," Nelson said.

He was paying well over $100 a month. He says he kept calling PG&E. The utility kept saying the charges were correct. This went on for years, until one day Nelson got a big surprise.

"There was no payment due and there was a credit of $1,199," Nelson said.

After all those charges, PG&E was giving him nearly $1,200 back. When he asked why, PG&E said, indeed, it had been overcharging him all those years.

"Their audit department discovered that the charge was wrong so that generated a credit for three years," Nelson said.

But PG&E only reimbursed him for three years. Nelson had been overcharged for seven years. He figured PG&E owed him around $1,600 more.

The utility said under state guidelines, it does not have to correct bills that are more than three years old.

"That's when I said, 'Well I will have to get 7 On Your Side involved,'" Nelson said.

7 On Your Side contacted PG&E and at first the utility agreed to give Nelson just $500 extra. However it turns out the case is much bigger than Nelson alone.

Sarkissian says everybody in Nelson's condo complex had been overcharged all these years -- not just Nelson. Residents in all 85 units will be getting money back too.

"We always want our customers to have a good experience and in this case we fell short and we do apologize," Sarkissian said.

All units here have permanent electric heating. That means they get to use more electricity before their rates jump to a higher tier. But somehow everyone had been listed as gas users, and was bumped to the higher rate.

And after our inquiries PG&E decided to waive the three-year limit for correcting bills -- everyone will get reimbursed for all years they lived there.

Nelson's expecting another $1,300 credit.

"Thanks to you guys because I don't think I would have got it without you guys," Nelson said.

If you have a permanent electric heating system you, too, are entitled to more electricity at the lower rate than are gas users. Check your bill. Look for the segment that tells your heating type. Make sure it's correct.